A blond-haired seventh grader who leads Team Blue Flare, a Digimon Army. Although he is in the same year as Taiki, he attends a so-called "elite school." Already, in the Digital World, due to his ingenious tactics and direct control over powerful Digimon, he subjugates a large number of Digimon. Anticipating Taiki's qualities, he once asked Taiki to become his subordinate but Taiki declined the offer, saying that Kiriha's eyes were not the eyes of a man who helped others out of kindness. His signature Digimon is MetalGreymon, a fusion of his MailBirdramon and Greymon.

Later, in the temple of the Digimon Temple, the legendary Digimon Deckerdramon chose Kiriha as his general over Taiki and Nene, stating that Kiriha held the strongest love in his heart, shocking Kiriha.

As the series goes on, Kiriha and Taiki became occasional allies and enemies. Whereas Taiki valued trust, friendship, and believed in all Digimon, Kiriha valued power and believed only in strong Digimon. These two values would clash multiple times through the season as Kiriha refused to help weak Digimon. The two would even battle each other on occasion, though both also teamed up to defeat the Bagra Army when necessary at times.

Gradually, Kiriha's stance toward Taiki changed, seeing him initially as a possible subordinate and then as a rival and enemy and finally as an ally and a friend. This relationship culminates in the sixth kingdom, when the death general lodges himself into Taiki's body, forcing Kiriha to either kill Taiki or surrender. Kiriha states that he can't possibly kill his friend and surrenders, showing his transformation over the series.

Later in the Digital Underworld, when Taiki was distraught over having to battle the now-evil Apollomon, Kiriha took charge, coming up with a successful plan that involved switching Digimon ownership in their team for the first time in the series, tricking the enemy and leading to Xros Heart's first victory against DarkKnightmon's team. Kiriha played the most dangerous role in the plan, becoming bait against Apollomon without any of the team's strongest Digimon to back him up.

Taiki's trust in Kiriha is further shown just before Taiki's soul is removed from his body. Taiki tells Kiriha that should he not return, Kiriha is to finish the mission.